Islands of the Giant Tortoises

Basking in the sun, soaking in muddy pools, and slowly
munching their vegetarian lunches, the giant Galápagos tortoises,
some over 150 years old, spend their lives in slow-motion.

The
Galápagos Islands were first discovered in 1535 by Tomas de Berlanga,
the bishop of Panama, when his ship drifted off course while on its way
to Peru. He named the Islands Las Encantadas, “The Enchanted,” and
marveled at the thousands of giant tortoises living there. Because of
these tortoises, the Islands became known as the Galápagos—the
Spanish word for tortoise.

Sailors—explorers, pirates and whalers, saw the huge tortoises,
which weigh up to 550 pounds, as a convenient source of fresh meat, for
the tortoises can survive long periods of time without food or water,
and can live in the hold of a ship for up to a year. When British naturalist
Charles Darwin visited the Galápagos in 1835, aboard the HMS Beagle,
the islands' residents showed him how to tell which island a tortoise
belonged to by the shape of its shell. Pondering the causes for this
localized diversity led Darwin to develop his Theory of Evolution.

At the time of his visit there were around a quarter of a million tortoises
living on the islands. Today less than 15,000 remain. Of the original
15 subspecies, only eleven are left—three have become extinct and
the fourth has only one individual left. Thousands of the animals were
slaughtered by the crews of sailing ships and, when the islands were
colonized in 1832, pigs, goats, rats and other animals also arrived,
eating eggs and young tortoises and destroying nests and food supplies.

It is believed that the tortoises, who can float on the sea for several
days, came to the Galapagos from the South American mainland. Once on
the islands they encountered no enemies. Each of the islands presented
its own unique environmental challenges, and the isolated tortoises evolved
to take advantage of these differences—tortoises on islands with
taller vegetation have longer necks.

Because of the tortoises extreme longevity, visitors to the Islands may
unknowingly photograph some of the same tortoises that Darwin himself
observed back in 1835.